Re: Self-referencing table question
От | Sean Davis |
---|---|
Тема | Re: Self-referencing table question |
Дата | |
Msg-id | 527567d18e0de8ad2c686699880f2bf0@mail.nih.gov обсуждение исходный текст |
Ответ на | Re: Self-referencing table question (Edmund Bacon <ebacon@onesystem.com>) |
Список | pgsql-sql |
On Mar 24, 2005, at 2:37 PM, Edmund Bacon wrote: > Sean Davis wrote: > >> Nice. Thanks for doing my work for me! > > Yeah, well put it down to a certain amount of curiosity and a slack > period at work ... > >> I guess I will have to think about it more seriously. >> >> It could be a slight bit complicated because my code is running under >> mod_perl, so connections are cached. As I understand it, the temp >> table will stick around, so I will have to be careful to explicitly >> drop it if I don't want it to persist? > > I'm guessing so. However you could put everything in a transaction > and use CREATE TEMP TABLE ... ON COMMIT DROP, and use INSERT INTO > rather than SELECT INTO. The speed should be about equivalent - but > you'd have to test to make sure. > >> Also each table will need a unique name (I have a session_id I can >> use), as it is possible that multiple temp tables will exist and be >> visible to each other? > > Each session (connection in your case?) has it's own temporary table > space, so you shouldn't have to worry about that. > Sessions don't map 1-to-1 with connections in the web environment. It is possible that a connection to the database would be simultaneously serving multiple users (sessions), if I understand Apache::DBI correctly. In any case, this is probably a viable solution. Sean
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